/* $Id: steps.h,v 1.5 2016/06/17 17:27:20 kili Exp $ */
/*
 * Copyright (c) 2016 Matthias Kilian <kili@outback.escape.de>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef TRISOLD_STEPS_H
#define TRISOLD_STEPS_H

/* Calculates all fields touched while walking from (x0, y0)
 * to (x0 + dx, y0 + dy), excluding the starting field (x0, y0).
 * For each field, the function *f() is invoked with the data pointer p
 * and with the current coordinates.
 * If *f() return a non-zero value v, the process is aborted and v is
 * returned. Otherwise, 0 will be returned.
 */
int walk_steps(int (*f) (void *d, int x, int y), void *d, int x0, int y0, int dx, int dy);

#endif